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Journal of Flow Visualization and Image Processing
SJR: 0.11 SNIP: 0.312 CiteScore™: 0.1

ISSN Print: 1065-3090
ISSN Online: 1940-4336

Journal of Flow Visualization and Image Processing

DOI: 10.1615/JFlowVisImageProc.v5.i2.60
pages 155-165

SPLITTING OF FORCED ELLIPTIC JETS AND FLAMES

John D. Carlton
Department of Mechanical Engineering, Center for Combustion and Environmental Research, University of Colorado, Boulder, Colorado
Jean R. Hertzberg
Department of Mechanical Engineering, Center for Combustion and Environmental Research, University of Colorado, Boulder, Colorado
E. Davis
Department of Mechanical Engineering, Center for Combustion and Environmental Research, University of Colorado, Boulder, Colorado
Mark Linne

ABSTRACT

A 'split' diffusion flame has been observed in response to high-amplitude axial velocity perturbations of the methane fuel jet. At specific excitation frequencies and amplitudes the driven flame splits into a central jet and one or two side jets. The splitting is accompanied by a partial detachment of the flame from the nozzle exit, a shortening of the flame by a factor of two, and a change from the common yellow color of soot radiation to a clear blue flame. Phase locked laser sheet flow visualization has been applied to reacting and nonreacting methane jets. Similar flow structures are observed in both reacting and nonreacting split jets. A roller-braid interaction similar to that seen in absolutely unstable jets may be responsible for the split flow, but additional features are observed.